Corrugated metal culvert



Nov. 24, 1936.. J. A. MORPHY CORRUGATED METAL CULVERTYI Filed June Patented Nov. 24, 1936 UNITED STATES PATENT OFFICE signor to The Firman L. Carswell Manufacturing' Company, Kansas City, Kans.

Application June 12,

4 Claims.

The principal objects of this invention are to provide a corrugated tubular metal culvert with a smooth bottom section which will present a free flow surface for water passing therethrough, and which will be strongly reinforced at the end throughout its entire circumference.

The principal feature of the invention consists in forming a metal sheet with corrugations partly surrounding the circumference leaving a smooth flow portion which is reinforced by a corrugation at the end extending completely therearound, the said corrugation being covered opposite the uncorrugated portion of the culvert by an overlapping extension from the mating end of the adjacent culvert length.

In the accompanying drawing, Figure 1 is a plan view of a metal sheet corrugated to form a culvert in accordance with this invention.

Figure 2 is a longitudinal vertical midsection through a pair of culvert sections constructed in accordance with this invention.

Figure 3 is a horizontal mid-section taken on the line 3-3 of Figure 2.

Figure 4 is an underside plan view of a group of sections connected together and forming a culvert.

Figure 5 is a reduced end elevational view showing the form of underside reinforcement for one end of the. culvert.

In the manufacture of sheet metal culverts it has been common practice to corrugate a sheet of metal lengthwise and to roll the sheet to form a tube with circumferential corrugations.

It has also been proposed to corrugate the sheet inwardly from the ends, leaving a central uncorrugated portion, which, when the sheet is rolled in tubular form, provides a smooth uncorrugated waterway in the bottom section.

It has been found however such culverts are liable to flatten across the uncorrugated portion, thus permitting an undesired sinking of the upper supporting circumference of the culvert. This difiiculty or deficiency has been partly eliminated by the attachment of a ribbed reinforcing strip arranged to extend circumferentially underneath the uncorrugated area, but such reinforcement has certain disadvantages as it must be held in place by bolts or rivets which may become loosened or displaced.

The present invention proposes the formation of a circumferential rib or ribs at one end of the culvert section which extends completely around the periphery of the culvert section and offers a sufficient and integral reinforcement for the uncorrugated portion.

1935, Serial No. 26,200

In forming up the sheet A the two end portions B are pressed to form a plurality of uniform corrugations C.s These extend inwardly from the ends leaving a central undeformedsection of the plate D. In the drawing of the metal to form the corrugations C the Width of the plate is of course lessened at the corrugated ends, but the central portion, which is uncorrugated, remains the full width of the sheet. This results in the curving of the longitudinal edges with outwardly extending and-curved edge central portions E. One of these curved central projections is preferably sheared off, and the first corrugation, at the sidev from which this portion is taken, is rolled to a deeper dimension than the remaining corrugations and this rolled corrugation is carried completely along the length of the sheet, thus forming a deepened reinforcing rib at that side of the sheet.

The sheet is then formed into tubular form with the overlapping ends being suitably riveted together in the usual manner. This leaves the projecting lip E opposite the smooth runway D.

In assembling the several sections of a culvert together the end with the projecting lip E is inserted inside of the deep ribbed end so that the lip E overlaps the hollow portion of the circumferential rib F, thus covering said hollow portion for the width of the smooth runway, and thereby providing a continuation of the smooth runway so that there will be no obstructions to cause eddy currents in the flow of water therethrough or to cause the deposit of sediment therein, which would ultimately tend to block the free flow of water through the culvert.

It will be understood that culverts are made up of several sections riveted together and the ribs F reinforce these sections and prevent the culvert from flattening at the smooth waterway portion in addition to presenting a stronger general circumferential reinforcement, but at one end of the completed culvert there will be no circumferential rib and at this end the smooth waterway portion D may be reinforced by a suitable ribbed semi-circular strip G shown in Figures 4 and 5.

It will be readily understood that a culvert constructed as herein described will require the minimum of manufacturing operating as the rolling of the extra rib or flange rib F will be accomplished during the operation of rolling the sheet into tubular form. The culvert will be exceptionally strong and will offer the minimum resistance to the flow of water therethrough.

What I claim as my invention is:-

1. A sheet metal culvert comprising a length of sheet metal having the ends thereof corrugated leaving the uncorrugated central portion its full width, the ends being joined together, one end of the culvert having a rolled reinforcing rib extending completely around the periphery and crossing and reinforcing the uncorrugated central portion of the culvert.

2. A metal culvert comprising a metal sheet having corrugations at each end and a smooth central portion having a continuous reinforcing rib corrugation extending along the length of one side, the sheet being rolled into tubular form and having a lip projected from the end of the culvert opposite to the ribbed end, to said lip being disposed in overlapped relation the rib recess in the adjacent culvert section to provide a smooth watershed thereover.

3. A sheet metal culvert of the corrugated smooth bottom form having a circumferential reinforcing corrugation at one end of more accentuated form than the body corrugations and bridging the smooth bottom portion between the body corrugations, and means carried by the other end of said culvert for bridging the channel formed by the accentuated reinforcing corrugation of a second similarly formed culvert.

4. A sheet metal culvert comprising a length of sheet metal having a central bottom portion undeformed and formed with a protruding lip at one end, the upper portion being corrugated circumferentially and the end opposite to the lip portion having a reinforcing circumferential corrugation extending completely therearound, and a ribbed reinforcement secured to the outer side of the lipped end of said culvert whereby the uncorrugated smooth lipped end is reinforced while presenting a smooth flow surface on the inward side.

JOHN A. MORPHY. 

